# Troubleshooting

| Error code | Error message                                                                                                                         | Description                                                                                                                                                                |
| ---------- | ------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| 401        | SDK is already initialized                                                                                                            | Trying to initialize multiple SDK Objects.                                                                                                                                 |
| 402        | Sender /Receiver is already running. HINT: Stop sender to start playing again.                                                        | This error is seen when the user tries to start the SDK receiver or sender method more than one time.                                                                      |
| 403        | SDK Not Initialised                                                                                                                   | The SDK Throws this error when SDK methods are being used without initialising SDK Object. Please make sure SDK objects are initialised properly before use.               |
| 404        | <p>Sender-only SDK doesn't support receiver</p><p>methods. HINT: create TrillSDK class with</p><p>the sender-only flag turned off</p> | This error is received when the user tries to initialise SDK without required permissions. SDK initialized with flag "Sender Only" and  does not support receiver methods. |
| 501        | Invalid SDK Key                                                                                                                       | Wrong SDK Key passed while creating TrillSDK object.                                                                                                                       |